Study protocol for a randomised trial evaluating the non-inferiority of stepped palliative care versus early integrated palliative care for patients with advanced lung cancer oleh Jennifer S Temel, Joseph A Greer, Pallavi Kumar, Kathryn E Post, Lauren B Heuer, Arif H Kamal, Madeleine Elyze, Sarah Griffith, Jacqueline Han, Fred Friedman, Ashley Jackson, Chardria Trotter, Rachel Plotke, Charu Vyas, Vicki Jackson, Dustin J Rabideau